Circadian: Your Natural Rhythm 4+

Wellness living & better sleep

Circadian Limited

    • 4.7 • 278 Ratings
    • Free
    • Offers In-App Purchases

iPhone Screenshots


Take your health into your own hands. Sync to circadian rhythms and give yourself the edge. Sleep, wake, eat, exercise and think at the optimal time for your body.

Ready for a lifestyle that prioritises your health and wellbeing?
Ready for living with more energy and focus?
Keen to naturally improve mood, body composition and sleep?

The answer? Do your daily activities at the optimal time for your body - aka circadian rhythms or the power of 'when'. ⏰

Enter Circadian, your app for applying circadian rhythms, and living a more natural lifestyle. Circadian uses your local solar time and some user settings to calculate your circadian rhythms, also known as biorhythm.

◾ Set reminders and alarms for critical circadian events
Being a biorhythm calculator, Circadian provides you with reminders & alarms to operate on your optimal biological schedule. Start sleeping, waking, eating, fasting, exercising and working when you are meant to. Set reminders or alarms for
- solar times (daybreak, sunrise, solar noon, sunset, nightfall)
- ultraviolet light rise and fall (UVA/UVB)
- sleep and wake times as well as a digital sunset
- eating and fasting times as well as meal timings
- morning and peak exercise times
- peak cognition times

◾ Adjust your sleep with the seasons
Circadian rhythms govern daily functioning, whereas seasonal rhythms, also referred to as infradian rhythms, affect longer-term behavioural and metabolic changes. Circadian can adjust your sleep duration dynamically based on the changing light conditions at your location. This keeps your bodies biorhythm in sync with seasonal changes.

◾ Feast and fast in line with natures pulse
Optimise your eating times and upgrade your intermittent fasting routine to a whole new level. Eating and fasting in sync with circadian and ultradian rhythms (less than a day) is essential if you want to reverse a metabolic disease or avoid getting one in the first place.

◾ Learn and implement with Circadian
The learn section provides you with carefully curated content on all things circadian rhythm related. Circadian is the most science-backed lifestyle app yet gives you the needed context fast.
- Dive deep into the thoroughly researched content
- Take action with our suite of practical suggestions
- Browse the best products to support your biorhythm
- Rest easy knowing that all content is based on more than 1000 scientific references

◾ The science behind circadian rhythms (chronobiology)
Your body's circadian rhythms are 24-hour cycles of biological, hormonal, and behavioural patterns. This biorhythm modulates a wide array of physiological processes, including your hormones, sleep, hunger, and metabolism, ultimately regulating body weight, performance, mood and susceptibility to disease. As such, circadian rhythmicity has profound implications for your wellbeing and longevity.

The 2017 Nobel price in medicine was given for research on circadian rhythms. Circadian clocks in almost all of your cells govern cellular functioning. When you disrupt your circadian clocks chaos, inflammation and disease are the natural consequence.

Artificial light or "junk light" is the main culprit for circadian disruptions. Which is why more natural light exposure, especially at sunrise and sunset, is crucial to reset and tune your biorhythm. Learn more in the app.

◾ Still doubtful?
Consider that circadian disruptions, and the ensuing inflammation, are linked to almost every modern disease from diabetes to cancer. Don't believe it? Search: "shift work" or "circadian rhythm" plus the name of a disease.

◾ What does Circadian cost?
Circadian offers a 7-day free trial period with some functionality and content restricted. You can continue using Circadian after the free trial with further limitations. For the full version, you need to subscribe or purchase the app (prices in USD):
Monthly subscription: $1.99 - $2.99
Yearly subscription: $12.99 - $19.99
One-off purchase: $49.99 - $74.99
You can find the terms & conditions here:

Follow natures pulse.
Increase your capacity for life!
Download Circadian now.

What’s New

Version 3.1.0

This version introduces a new pricing structure and improved workflows.
We're actively working to improve Circadian.
Here's to optimising our circadian rhythms and lifestyle one step at a time. Feel free to contact us at if you have any issues, feedback, suggestions or questions.
Mind your rhythm, mind your light

Team Circadian

Ratings and Reviews

4.7 out of 5
278 Ratings

278 Ratings

Eddiemoto ,

Simple and great. Info and learning is the hidden jewel.

I’m learning about Circadian rhythm and how to use the information to approach my day differently. The informing provided within the app is the real jewel. I’m learning a lot. **The Good** - The My Day tab is very straight forward. I love how easy it is to setup a notification from the details screen. - The Dashboard tab is clear and effective. - The Learn tab is absolutely full of great information. Awesome. **Ideas for Improvement** - An alternative view of the dashboard that displayed information in a linear fashion along with the peaks and dips. - Peaks and dips could be annotated in My Day. - Suggestions. For instance, it would be nice to say something like "Study for test" or "Nap" and have suggestions on when a good time to do that activity may be.
- I would love some Apple Watch visibility and complications.
**Next Level** - It would be nice to take some simple notes throughout the day and see a note icon on the dashboard repressing when that note was annotated. - A historical view would be nice that included any notes. - Sleep Debt. This would be 100% amazing. I realize it is a little out of scope, but for folks that track sleep debt, circadian rhythms are important.

Developer Response ,

Thank you very much for your thoughtful review, Ed! Great to hear that you appreciate Circadian. We really value your input and have added all your suggestions to our list of requested features. If you have any questions or further input please be in touch! See you outside, Bastian | Team Circadian

cepoils ,

Great accountability & teaching tool!

I’ve already started implementing some of the habits and lifestyle changes more in tune with a balanced circadian lifestyle. But this app helps keep me on track and accountable on days when I need reminders or suggestions on how to improve my habits such as eating to close to bedtime and reminding me to go watch the sunset. I already see an improvement in my energy and cognitive function. The app has subtle notifications like a bird tweeting to remind you of the next step in your day. You can adjust these to your preference and modify your schedule as you go. I highly recommend this app for anyone who cares about improving their health and wants to make it as simple as possible. I’m still on the free trial so may have missed this but 1 suggestion I’d make is to add a grounding feature in the routine options and for those who love to check things off their lists, add the option to check things off daily once completed. Overall, super impressed! Thanks!

Developer Response ,

Thank you very much for your comprehensive review! Great to hear that your energy and cognition improved already! And thank you for your suggestion as well. We will add the ability to add custom events soon, tracking features will come too but this is a bit further down the road. Any questions or further feedback please be in touch via in-app messages or send an email to See you out there! Bastian | Team Circadian

htreitman ,

My second most used app!

The creator announced this app just when I was at my wits’ end with trying to gather accurate and comprehensive information on my many circadian lifestyle questions. The articles I generally found online were either extremely superficial or scientifically way over my head. This app’s “Learn“ section alone is worth the price of the annual subscription to me. I am relying on the reminders “Circadian” sends me throughout the day to help me establish the habits I was confused about before, and a satisfying answer to the question “why?“ is always a click away. It is taking the burden of a lot of confusing research off my shoulders so I can focus on my priorities. The app creator welcomes feedback and at this stage is available to answer questions directly. (My most used app is my iPhone “Notes.” Then comes “Circadian.”)

Developer Response ,

Thank you so much, Helaine! Great that Circadian helps you implementing a natural lifestyle and answers your questions about circadian rhythms. That is exactly what we set out to do. It is exciting to see that Circadian is well received even in these early days. We are looking forward to turning Circadian into something truly amazing. And yes, we love feedback from all users. If you have any more ideas please be in touch. Lots of gratitude 🙏, Bastian, team Circadian

App Privacy

The developer, Circadian Limited, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Linked to You

The following data may be collected and linked to your identity:

  • Location
  • Identifiers

Privacy practices may vary, for example, based on the features you use or your age. Learn More


  • Family Sharing

    Some in‑app purchases, including subscriptions, may be shareable with your family group when Family Sharing is enabled.

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